对AZ31B镁合金焊接接头和热影响区的疲劳裂纹扩展行为进行研究,分析了焊接接头[L-T(W)]和热影响区的紧凑拉伸试验[C(T)],其中热影响区的C(T)试验包括焊缝平行于挤压方向[T-L(H)]和垂直于挤压方向[L-T(H)]两种.结果表明:对于L-T(W)试样,裂纹沿挤压方向扩展,裂纹扩展经历先快后慢的扩展过程；T-L(H)试样裂纹平行于缺口方向扩展,L-T(H)试样裂纹为平行于缺口方向和与缺口成一定角度两种扩展方向,裂纹扩展经历先慢后快的扩展过程.裂纹尖端扩展为穿晶和沿晶的混合模式,疲劳断口为准解理特征的脆性断口.
The fatigue crack propagation behavior of as-extruded AZ31B magnesium alloy welded joint and heat affected zone have been studied.Compact tensions [C(T)] of welded joint [L-T(W)] and heat affected zone(welded joint is parallel [T-L(H)]and vertical [L-T(H)] to the extruded direction) were researched.Results indicate that the crack propagation direction is parallel to the extrusion direction for L-T(W); fatigue crack propagation rate is a rapid-slow process.T-L(H) is parallel to the notch direction and L-T(H) can be divided into two states (i.e.,parallel to or angularly deflected towards the notch direction);crack propagation rate initially goes through a rapid course before it slows down.The fracture modes of crack tip remain a mixed-mode of transgranular and intergranular fractures.The fatigue fracture consists of quasi-cleavage and is a brittle fracture.
参考文献
| [1] | Keiro Tokaji;Masaki Nakajima;Yoshihiko Uematsu .Fatigue crack propagation and fracture mechanisms of wrought magnesium alloys in different environments[J].International Journal of Fatigue,2009(7):1137-1143. |
| [2] | Luo T J;Yang Y S;Tong W H et al.[J].Materials & Design,2010,31:1617. |
| [3] | 陈振华.变形镁合金[M].北京:化学工业出版社,2005:1. |
| [4] | Sotomi Ishihara;Zhenyu Nan;Takahito Goshima .Effect of microstructure on fatigue behavior of AZ31 magnesium alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2007(0):214-222. |
| [5] | Nan Z Y;Ishihara S;McEvily A J et al.[J].Scripta Materialia,2007,56(08):649. |
| [6] | Xu D K;Liu L;Xu Y B et al.[J].Journal of Alloys and Compounds,2007,431:107. |
| [7] | Park S S;Tang W N;You B S .[J].Materials Letters,2010,64:31. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%